Pneumatic height-adjustable desk

ABSTRACT

A pneumatic height-adjustable desk may comprise two legs, two pneumatic rods, two pulleys units, a cross beam, a control spindle, a clutch unit and a desk top. By cooperating the pneumatic rods, the pulleys units, the control spindle and the clutch unit, the two sides of the desk top are configured to go up or down synchronously and maintain even in the raising or lowering process. Also, by using the clutch unit to clamp the control spindle, the desk top is configured to firmly maintain flat and stable even the single side of the desk top is pressed by the heavy stuff.

FIELD OF THE INVENTION

The present invention relates to a pneumatic height-adjustable desk, and more particularly to a pneumatic height-adjustable desk capable of synchronously adjusting the heights of two legs.

BACKGROUND OF THE INVENTION

With the enhancement of people's living standards, a height-adjustable desk is more used for fitting users with different heights or allowing a user to use when standing. Currently, there are two popular types of height-adjustable desks in the market which respectively have single and twin pneumatic units.

However, these conventional pneumatic height-adjustable desks have following disadvantages: (i) when a user uses a height-adjustable desk with single pneumatic unit, it may happen that two sides of a desk top are in different heights; and (ii) on the other hand, although a height-adjustable desk with twin pneumatic units can solve the problem the single pneumatic unit met, it is still lack that the adjusting process of heights of two legs are always not synchronized. Also, when a desk top has heavy stuffs put on one side thereof, which causes the two pneumatic units to hold unequal pressures, the desk top may be tilted. Furthermore, when the user adjusts the height of the desk in this situation, the pneumatic units may get stuck. Therefore, there remains a need for a new and improved design for a pneumatic height-adjustable desk to overcome the problems presented above.

SUMMARY OF THE INVENTION

The present invention provides a pneumatic height-adjustable desk which comprises two legs, two pneumatic rods, two pulleys units, a cross beam, a control spindle, a clutch unit and a desk top. Each of two legs has an outer tube, and an inner tube is movably received in the outer tube to achieve telescoping effect. Each of two lower ends of the two inner tubes is connected to a foot which is configured to increase a contacting area and allow the pneumatic height-adjustable desk to firmly stand on a floor. Each of two upper ends of the outer tubes is connected to a supporting base which has an accommodating space, and an interior space of the outer tube is communicated with the accommodating space of the supporting base. Each of the two pneumatic rods comprises a cylindrical body, and a pushing rod movably received in the cylindrical body is pushed by air pressure to extend outwardly at standard condition. The pneumatic rod is received in the inner tube and the outer tube to allow two respective upper ends of the cylindrical body and the pushing rod to connect with the two supporting bases and allow two respective lower ends thereof to connect with the two feet. Each of the two pulleys units has a first pulley and a second pulley which are respectively pivotally connected on the upper end and the lower end of the cylindrical body, and a round belt is disposed on the first pulley and the second pulley as a chain. When the two pneumatic rods with the two pulleys units are respectively settled inside the two legs, each of the two first pulleys protrudes from the outer tube and is positioned inside the accommodating space of the supporting base. A locating piece secured on an upper portion of the inner tube is connected to a clamping piece which is configured to clamp the round belt thus building the connection between the inner tube and the round belt. The cross beam secured between two upper ends of the two outer tubes comprises a housing space, and an elongated opening is formed at a top end thereof such that the control spindle with the clutch unit is configured to put into the housing space of the cross beam through the elongated opening. The clutch unit is mounted on the control spindle, and an outer periphery of the control spindle has a polygon-shaped section. When the control spindle with the clutch unit is put into the housing space of the cross beam, each of two ends of the control spindle is engaged with an engaging hole of the first pulley through the polygon-shaped section. The clutch unit is configured to engage and disengage with the control spindle, and the control spindle is configured to achieve power transmission to stop or synchronously rotate the two first pulleys. The desk top is secured on the two supporting bases and the cross beam, and a control unit settled on a lower surface of the desk top is electrically connected to the clutch unit.

Comparing with conventional pneumatic height-adjustable desk, the present invention is advantageous because: (i) by cooperating the pneumatic rods, the pulleys units, the control spindle and the clutch unit, the two sides of the desk top are configured to go up or down synchronously and maintain even; and (ii) by using the clutch unit to clamp the control spindle, the desk top is configured to firmly maintain flat and stable even the single side of the desk top is pressed by the heavy stuff.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a three-dimensional assembly view of a pneumatic height-adjustable desk in the present invention.

FIG. 2 is a three-dimensional exploded view of the pneumatic height-adjustable desk in the present invention.

FIG. 3 is a detailed exploded view of a leg of the pneumatic height-adjustable desk in the present invention.

FIG. 4 is a detailed exploded view of a clutch unit of the pneumatic height-adjustable desk in the present invention.

FIG. 5 is a plane assembly view of the pneumatic height-adjustable desk in the present invention.

FIG. 6 is a sectional assembly view of the pneumatic height-adjustable desk in the present invention.

FIG. 7 is a schematic view illustrating the clutch unit clamps and stops the spinning of a control spindle of the pneumatic height-adjustable desk in the present invention.

FIG. 8 is a schematic view illustrating the clutch unit releases the control spindle of the pneumatic height-adjustable desk in the present invention.

FIG. 9 is a sectional view illustrating the height of a desk top of the pneumatic height-adjustable desk in the present invention is raised.

DETAILED DESCRIPTION OF THE INVENTION

The detailed description set forth below is intended as a description of the presently exemplary device provided in accordance with aspects of the present invention and is not intended to represent the only forms in which the present invention may be prepared or utilized. It is to be understood, rather, that the same or equivalent functions and components may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs. Although any methods, devices and materials similar or equivalent to those described can be used in the practice or testing of the invention, the exemplary methods, devices and materials are now described.

All publications mentioned are incorporated by reference for the purpose of describing and disclosing, for example, the designs and methodologies that are described in the publications that might be used in connection with the presently described invention. The publications listed or discussed above, below and throughout the text are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the inventors are not entitled to antedate such disclosure by virtue of prior invention.

In order to further understand the goal, characteristics and effect of the present invention, a number of embodiments along with the drawings are illustrated as following:

Referring to FIGS. 1 to 7, the present invention provides a pneumatic height-adjustable desk which comprises two legs (10), two pneumatic rods (20), two pulleys units (30), a cross beam (40), a control spindle (50), a clutch unit (60) and a desk top (70). Each of two legs (10) has an outer tube (12), and an inner tube (11) is movably received in the outer tube (12) to achieve telescoping effect. Each of two lower ends of the two inner tubes (11) is connected to a foot (13) which is configured to increase a contacting area and allow the pneumatic height-adjustable desk to firmly stand on a floor. Each of two upper ends of the outer tubes (12) is connected to a supporting base (14) which has an accommodating space, and an interior space of the outer tube (12) is communicated with the accommodating space of the supporting base (14). Each of the two pneumatic rods (20) comprises a cylindrical body (21), and a pushing rod (22) movably received in the cylindrical body (21) is pushed by air pressure to extend outwardly at standard condition. The pneumatic rod (20) is received in the inner tube (11) and the outer tube (12) to allow two respective upper ends of the cylindrical body (21) and the pushing rod (22) to connect with the two supporting bases (14) and allow two respective lower ends thereof to connect with the two feet (13). Each of the two pulleys units (30) has a first pulley (31) and a second pulley (32) which are respectively pivotally connected on the upper end and the lower end of the cylindrical body (21), and a round belt (33) is disposed on the first pulley (31) and the second pulley (32) as a chain. When the two pneumatic rods (20) with the two pulleys units (30) are respectively settled inside the two legs (10), each of the two first pulleys (31) protrudes from the outer tube (12) and is positioned inside the accommodating space of the supporting base (14). A locating piece (34) secured on an upper portion of the inner tube (11) is connected to a clamping piece (35) which is configured to clamp the round belt (33) thus building the connection between the inner tube (11) and the round belt (33). The cross beam (40) secured between two upper ends of the two outer tubes (12) comprises a housing space (41), and an elongated opening is formed at a top end thereof such that the control spindle (50) with the clutch unit (60) is configured to put into the housing space (41) of the cross beam (40) through the elongated opening. The clutch unit (60) is mounted on the control spindle (50), and an outer periphery of the control spindle (50) has a polygon-shaped section (51). When the control spindle (50) with the clutch unit (60) is put into the housing space (41) of the cross beam (40), each of two ends of the control spindle (50) is engaged with an engaging hole (311) of the first pulley (31) through the polygon-shaped section (51). The clutch unit (60) is configured to engage and disengage with the control spindle (50), and the control spindle (50) is configured to achieve power transmission to stop or synchronously rotate the two first pulleys (31). The desk top (70) is secured on the two supporting bases (14) and the cross beam (40), and a control unit (71) settled on a lower surface of the desk top (70) is electrically connected to the clutch unit (60).

In one embodiment, a top end of the inner tube (11) has a first cover (15), and at least two first sliding wheels (151) are pivotally connected to the first cover (15) are configured to bear against an inner surface of the outer tube (12) thus allowing the inner tube (11) and the outer tube (12) to achieve extending and retracting actions smoothly and preventing the pneumatic height-adjustable desk from shaking during the extending or retracting process due to a gap formed between the inner tube (11) and the outer tube (12).

In another embodiment, a bottom end of the outer tube (12) comprises a second cover (16), and at least two second sliding wheels are pivotally connected to the second cover (16) are configured to bear against an outer surface of the inner tube (11) thus allowing the inner tube (11) and the outer tube (12) to achieve extending and retracting actions smoothly and preventing the pneumatic height-adjustable desk from shaking during the extending or retracting process due to the gap formed between the inner tube (11) and the outer tube (12).

In still another embodiment, the clutch unit (60) has a fixing base (61) which is secured on the lower surface of the desk top (70), and a lateral surface of the fixing base (61) comprises a stepped hole (611) which is configured to be penetrated through by the control spindle (50). The stepped hole (611) is further engaged with a horizontal moving unit (63), and a spring (62) is borne against an inner edge of the horizontal moving unit (63) and the fixing base (61) on both sides thereof. A plurality of gear slots (631) are formed at an inner periphery of the horizontal moving unit (63), and by using the spring (62) to push the horizontal moving unit (63) to move away from the fixing base (61), the gear slots (631) are configured to engage with an gear (64) formed on the control spindle (50). As a result, because of the engagement among the fixing base (61), the horizontal moving unit (63), the gear (64) and the control spindle (50), the control spindle (50) is unable to be rotated (as shown in FIGS. 4 to 7). On the other hand, since an operating arm (65) mounted on the fixing base (61) is electrically connected to the control unit (71), through pressing a button on the control unit (71), the operating arm (65) is driven to push the horizontal moving unit (63) toward the fixing base (61) such that the gear (64) is disengaged with the gear slots (631) of the horizontal moving unit (63) thereby allowing the control spindle (50) to spin independently (as shown in FIG. 8).

In actual application, a user can raise the height of the desk top (70) by pressing the button of the control unit (71) such that the clutch unit (60) is configured to release and allow the control spindle (50) to spin independently. Also, since the two ends of the control spindle (50) are respectively connected to the two first pulleys (31) supported by the two pushing rods (22) which are continuously extended, the two round belts (33) are configured to drive the outer tubes (12) to move upwardly thus raising the height of the desk top (70) (as shown in FIG. 9). On the contrary, a user can lower the height of the desk top (70) by pressing the button of the control unit (71) to release the control spindle (50), and use a hand to press down the desk top (70) till a desirable height, and then release the button of the control unit (71) to allow the clutch unit (60) to re-engage with the control spindle (50). Thus, since the control spindle (50) is clamped by the clutch unit (60) to stop spinning, the two pulleys units (30) are also stopped rotating such that the lowering process is stopped and the height of the desk top (70) is firmly secured even the pushing rods (22) are pushed by air pressure to keep extending at standard condition thereby securing positions of the two outer tubes (12). Moreover, since the clutch unit (60) is configured to firmly clamp the control spindle (50), which prevents the pneumatic rod (20) from stuck during the raising and lowering process when a single side of the desk top (70) is pressed by a heavy stuff, the desk top (70) is configured to always maintain even and stable.

Comparing with conventional pneumatic height-adjustable desk, the present invention is advantageous because: (i) by cooperating the pneumatic rods (20), the pulleys units (30), the control spindle (50) and the clutch unit (60), the two sides of the desk top (70) are configured to go up or down synchronously and maintain even; and (ii) by using the clutch unit (60) to clamp the control spindle (50), the desk top (70) is configured to firmly maintain flat and stable even the single side of the desk top (70) is pressed by the heavy stuff.

Having described the invention by the description and illustrations above, it should be understood that these are exemplary of the invention and are not to be considered as limiting. Accordingly, the invention is not to be considered as limited by the foregoing description, but includes any equivalents. 

What is claimed is:
 1. A pneumatic height-adjustable desk comprising: two legs respectively having an outer tube, and an inner tube movably received in the outer tube to achieve a telescoping effect, and each of two lower ends of the two inner tubes connected to a foot which is configured to increase a contacting area and allow the pneumatic height-adjustable desk to firmly stand on a floor; each of two upper ends of the outer tubes connected to a supporting base which has an accommodating space, and an interior space of the outer tube communicated with the accommodating space of the supporting base; two pneumatic rods respectively comprising a cylindrical body, and a pushing rod, which is movably received in the cylindrical body, pushed by air pressure to extend outwardly at standard condition; the pneumatic rod received in the inner tube and the outer tube to allow two respective upper ends of the cylindrical body and the pushing rod to connect with the two supporting bases and to allow two respective lower ends of the cylindrical body and the pushing rod to connect with the two feet; two pulleys units respectively having a first pulley and a second pulley which are pivotally connected on the upper end and the lower end of the cylindrical body respectively, and each of two round belts disposed on the first pulley and the second pulley as a chain; when the pneumatic rod with the pulleys unit settled inside each of the legs, each of the two first pulleys protruding from the upper end of the outer tube and positioned inside the accommodating space of the supporting base; a locating piece, which is secured on an upper portion of the inner tube, connected to a clamping piece which is configured to clamp the round belt thereby building the connection between the inner tube and the round belt; a cross beam, which is secured between the two upper ends of the two outer tubes, comprising a housing space, and an elongated opening, which is formed at a top end of the housing space, configured to allow a control spindle with a clutch unit to put into the housing space of the cross beam; the control spindle having the clutch unit mounted thereon, and an outer periphery of the control spindle having a polygon-shaped section; when the control spindle with the clutch unit put into the housing space of the cross beam, each of two ends of the control spindle engaged with an engaging hole of the first pulley through the polygon-shaped section; the clutch unit configured to clamp or release the control spindle, and the control spindle configured to achieve power transmission to stop or rotate the two first pulleys synchronously; and a desk top secured on the two supporting bases and the cross beam, and a control unit, which is settled on a lower surface of the desk top, electrically connected to the clutch unit.
 2. The pneumatic height-adjustable desk of claim 1, wherein the upper end of the inner tube has a first cover, and at least two first sliding wheels are pivotally connected to the first cover.
 3. The pneumatic height-adjustable desk of claim 1, wherein a bottom end of the outer tube comprises a second cover, and at least two second sliding wheels are pivotally connected to the second cover.
 4. The pneumatic height-adjustable desk of claim 1, wherein the clutch unit has a fixing base which is secured on the lower surface of the desk top, and a lateral surface of the fixing base comprises a stepped hole which is configured to be penetrated through by the control spindle; wherein the stepped hole is further engaged with a horizontal moving unit, and a spring is borne against an inner edge of the horizontal moving unit and the fixing base respectively on both sides thereof; a plurality of gear slots are formed at an inner periphery of the horizontal moving unit, and by using the spring to push the horizontal moving unit to move away from the fixing base, the gear slots are configured to engage with an gear formed on the control spindle, and with the engagement among the fixing base, the horizontal moving unit, the gear and the control spindle, the control spindle is fixed and immovable; wherein the clutch unit further has an operating arm which is mounted on the fixing base and electrically connected to the control unit, and through pressing a button on the control unit, the operating arm is driven to push the horizontal moving unit toward the fixing base such that the gear is disengaged with the gear slots of the horizontal moving unit thereby allowing the control spindle to spin. 